Primary Hyperparathyroidism due to Ectopic Intrathymic Parathyroid Adenoma in A Child: A Case Report

Abstract

Primary hyperparathyroidism (PHPT) is a rare endocrine disorder in children and adolescents. Surgery is curative in most pediatric patients with PHPT. PHPT due to ectopic parathyroid adenoma (EPA) presents the difficulty of their exact topographic diagnosis and there is no consensus for the optimal imaging modality. The 99mTc-sestamibi (99mTechnetium -labeled methoxy-isobutyl-isonitrile) scintigraphy appears to be the best exam to establish a topographic diagnosis of parathyroid adenoma. Herein, we present the case of a 14-year-old girl with the diagnosis of PHPT with bone involvement. Parathyroid scintigraphy (dual-phase and dual tracer subtraction imaging), has shown an abnormal tracer uptake in the anterior mediastinum. Computed tomography (CT), has confirmed the mediastinal seat of the adenoma, measured 40 x 24.6 mm, repressing the thymus. An adenectomy was performed using video-assisted mini-thoracoscopic surgery. Histological findings have shown intrathymic ectopic parathyroid adenoma. After surgery, the patient had profound and persistent hypocalcemia as a result of extensive remineralization in a relation to Hungry Bone Syndrome (HBS). Through this clinical report, we insist on the importance of preoperative localization of parathyroid adenoma to select the surgical approach and to avoid failed cervicotomy especially in cases of ectopic adenomas.